Impregnating wood.



although alkaline in' reaction,

UNITED STATES WILLIAM B. CHISOLM, 0F CHARLESTON, SOUTH CAROLINA.

IMPREGNATING woonl 80 Drawing.

To all whom it may concern:

Be it known that I, WILLIAM B. CHIBOLM, a citizen of the United States, residing at Charleston, in the county of Charleston, in the State of South Carolina, have invented certain new and useful Improvements in Impregnating Wood; and I dohereby declare the following to be a full,.clear, and exact description of the invention, such as will enable others it appertains to make and use the same.

In a. oopending application for Letters Patent of the United. btates, Serial N umber 47L237, I have described the impregnation of wood for the purpose of preserving it from decay, by means of a solution containing sulfur chemically combined and sulfur in a practically free state. I

In the practice of the invention described in my said application, I have chosen as a typical embodiment thereof the impregnation of wood by a. solution made up b011- ing sulfur and lime in tion of four parts by weight of sulfur to one part by Weight of lime. On account of the relative proportions of the sulfur and lime In this particular embodiment of the invention described in said application, thefinal solution. used or impregnating the w ood, contains no substantial excess of free alkali.

The purpose of my present invention is employ as the impreiplating solution, one which not on y alka e in its character, but which carries a considerable excess of free alkali. The function of having an excess of alkali-in the impregnating solution is twofold; first, it increases the capillary acti ity of the solution, enabling it to more readiiy penetrate the wood. and secondly, the caustic alkali exerts a hydrolyzing action upon the cellulose. Furthermore, in addit-ion to these effects, the caustic alkali forms a send-solution of certain portions of the lignin matter of the wood, converting-them into a material of a slightly gummy or viscous character, which, when dried, hardens and acts as a sizing matter throughout the Wood. This hardeni' of the wood is accompanied with the ormation therein of new chemical compounds of very complex character. The effect is to cause the Wood to shrink, thereby making it denser and better adapted to hold within the Wood the free sulfur dcpositml from the solution in time and also the sulfur compounds, of whatever Specification of Letters Patent. Application filed August 16, 1909.

skilled in the art to which,

water in the proper Serial No. 513,039.

character that remain therein. As a consequence, there is less tendency for any of the soluble sulfur compounds with which the wood is impregnated to leach out, because of the fact that they are surrounded or enveloped in this hydrolyzing and gelatinized mass.

In putting the invention into practice, I may boil together in water a mixture of an alkali such as slaked limo (calcium hydroxid) and sulfur in. the proportions by weight of one part of sulfur to one part of calcium hydroxid. These equal proportions will give a resulting solution that contains a slight excess of caustic alkali sufiicient to develop a certain feet, but I prefer to use a larger portion of the caustic alkali, as, for instance, by forming the mixture of three parts hy weight of calcium hydroxid to two by Weight of sulfur. This additional amount of caustic alkali in the solution will be sufficient when used at or near the boiling temperature to fully develop the hydrolyzing, gelatinizing and hurdci'ling functions desired.

A solution made in the manner described carries not only free alkali but more or less dissolved sulfur which is in a free. or potentially free state, and also sulfur in a state of combination which is readily broken up so that the liquid will deposit sulfur on cooling and in time. This dissolved sulfur which is in a state oi solution at the time of impregnating the Wood and enters the Wood in that state, and subsequently separates in a free or elemental form may be regarded as free or potentially free sulfur.

The impregnation of the WOO-l may be eilected in any of the usual or preferred methods, as, for example, by the 1 uni vacuum and pressure processes, and pit ably at the boiling point of the solution. in wood'so iul 'negnated there \villbe deposited a large proportion of sulfur, both in the free and in the combined foru'l, the sell it being partly in the free or elemental form and partly in the form ofsulfur compounds Which become more and more insoluble under the oii'cct of subsequent chemical change,

Having thus describedv my invention, what I claim is: e

1. The method of treating wood. which consists in impregating its pores with an aqueous solution carrying combined sulfur and also carrying free sulfur, togetl'ler with degree ofhardening cf Patented July 26,1910.

com rises im re natin its ores with an I aqueous solution carrying combined sulfur Correction in Letters PatenLNa 965,154.

and also free sulfur together with an excess of lime, such lime bein present in amount sufiicient to partly hydrolyze the cellulose and partly gelatinize the lignin of the wood.

3. The method of treating wood which- 'coi nprises impregnating its pores with a boiling aqueous solution carrying combined sulfur and also free sulfur together with an excess of lime, such lime being present in [SEAL] upon the application of William B. Chisolm, of Charleston,

should read laq llrolized; and that the said Letters amount sufficient to partly hydrolyzethe cellulose and partly gelatinize the lignin of the wood.

4. As a new article of manufacture, wood whose cellulose is partially hydrolyzed and whose lignin is partially gelatinized, said wood being likewise impregnated with free sulfur andwith combined sulfur; substantially as described.

In testimony whereof I afiix my signature, in presence of two Witnesses.

WILLIAM B. CHISOLM.

Witnesses:

JOHN C. PENNIE, LAURA B. PENFIELD.

It is herehy certified that in Letters Patent No. 965,154, granted July 26,1910, I

South Carolina, for an improvement in Impregnating Wood, an error appears in the printed specification requiring correction as follows: Page 1, line 62, the word hydrolizing Patent should be read with this correction therein that the same may conform to the record of the ease in the Pat- Signed and sealed this 30th day of Ai'lgust, A. D,, 1910.

F. A. TEUNANT,

Acting Corny/wished:er of Patents.

com rises im re natin its ores with an I aqueous solution carrying combined sulfur Correction in Letters PatenLNa 965,154.

and also free sulfur together with an excess of lime, such lime bein present in amount sufiicient to partly hydrolyze the cellulose and partly gelatinize the lignin of the wood.

3. The method of treating wood which- 'coi nprises impregnating its pores with a boiling aqueous solution carrying combined sulfur and also free sulfur together with an excess of lime, such lime being present in [SEAL] upon the application of William B. Chisolm, of Charleston,

should read laq llrolized; and that the said Letters amount sufficient to partly hydrolyzethe cellulose and partly gelatinize the lignin of the wood.

4. As a new article of manufacture, wood whose cellulose is partially hydrolyzed and whose lignin is partially gelatinized, said wood being likewise impregnated with free sulfur andwith combined sulfur; substantially as described.

In testimony whereof I afiix my signature, in presence of two Witnesses.

WILLIAM B. CHISOLM.

Witnesses:

JOHN C. PENNIE, LAURA B. PENFIELD.

It is herehy certified that in Letters Patent No. 965,154, granted July 26,1910, I

South Carolina, for an improvement in Impregnating Wood, an error appears in the printed specification requiring correction as follows: Page 1, line 62, the word hydrolizing Patent should be read with this correction therein that the same may conform to the record of the ease in the Pat- Signed and sealed this 30th day of Ai'lgust, A. D,, 1910.

F. A. TEUNANT,

Acting Corny/wished:er of Patents.

It is horohy certified that in Letters Patent No. 065.154, granted July 26., 1910, upon the application of William ll. Chisolm, of Charleston, South Carolina, for an improvement in Imprcgnating Wood, an orror appears in the printed specificu tion requiring coriovtion m follows: Page 1, lino 62, the Word hydrolizing should read b dml'zlzwl; and that the said Letters Patent should be read with this correction thoroin that the smile may conform to the record of the casein the Pub ent ()flice.

Signor] and sealed this 30th (lay of August, A. 1 1910.

[SEAL] l. A. 'IENNAN'I,

Correction in Letters Patent.N0. 965,154. 

